As the downscaling of semiconductor devices progresses, it is necessary to form fine patterns equal to or less than the resolution limit of the lithography. As a method for realizing this, a so-called sidewall transfer process has been proposed in which sidewall films are formed on side walls extending in a longitudinal direction of sacrificial films (core members) formed by lithography in line configurations, and subsequently the sacrificial films are removed and the sidewall films remain.
In the case where, for example, a fine interconnect pattern is formed by such a sidewall transfer process, an interconnect pattern having a line width corresponding to the film thickness of the sidewall film can be formed. However, generally, in the interconnect pattern of an actual semiconductor device, broad patterns are disposed here and there in the pattern layout to provide connections to the interconnect layers above and below by vias.